These stable non-toxic silicone fluids are accurate to ±1% of the stated viscosity and are calibrated by methods traceable to the National Institute of Standards and Technology (NIST). The selection of two or three fluids will normally provide sufficient points of calibration. Calibrated at 25°C (77°F). Viscosity blends and temperature calibrations (other than those listed) are available as special order fluids. Supplied with Certificate of Calibration. 500 ml bottle.